Mercedes-Benz AMG GLE 53
Return to the inline-six after years of the M276 V6 — and the difference is immediately noticeable. Smoother, more even rev build-up, torque plateau from 1,600–4,000 rpm without any weakness. The 48V mild-hybrid system with integrated starter-generator (ISG) is not a marketing term: 16 kW of boost on pull-away fills turbo lag completely; measurable fuel saving in sail mode. When buying, check the 48V battery — failure costs 2,000–4,000 EUR, primarily affecting build years up to 2022. Electric coolant pumps can fail from 80,000 km. Change oil every 10,000 km, do not rely on Longlife — HPFP and camshaft adjusters are sensitive to old oil. Cold-start wastegate bushing rattle is by design and not a fault. Overall a very accomplished engine that holds 250,000 km without issues when maintained correctly.
GLE 53 AMG — the Best GLE on the Motorway
320 kW in the GLE — the inline-six revs smoothly, the 9-speed gearbox shifts seamlessly. Compared to the GLE 450, the extra power is perceptibly available for overtaking at any moment. Not an agile sports car, but a supremely composed motorway presence. AMG suspension firmer than the 450, but not uncomfortable.
Engine Weaknesses 9
Frequently reported problem: 48V battery of the EQ Boost system fails and costs 2,000–4,000 EUR to replace. Design issue with earth connection in early vehicles.
Symptoms: EQ Boost deactivated, start-stop system failed, hybrid warning light, sporadic starting problems
The known Mercedes problem of leaking camshaft solenoids also affects the M256 (same solenoid technology as M276/M270). Oil migrates by capillary action and destroys lambda sensors and the ECU.
Symptoms: Lambda sensor fault codes, MIL, rough running. Multiple electrical faults simultaneously as it progresses
M256 shows elevated oil consumption from approx. 100,000 km, attributable to the PCV system and cylinder walls. Regular oil level checks necessary.
Symptoms: Dropping oil level, occasional bluish smoke after warm-up phase
The beltless M256 operates exclusively electric coolant pumps. Pump motors fail internally and trigger temperature warnings. Bleeding requires specialist diagnostic equipment.
Symptoms: Coolant temperature warning, irregular operating temperature, occasional overheating warning
The camshaft-driven high-pressure pump on the M256 can wear prematurely with irregular oil changes. Injectors can be damaged by metal debris.
Symptoms: Fuel pressure fault codes, rough idle, starting problems, hesitation under load, elevated fuel consumption
With predominantly short-trip use the OPF cannot fully regenerate. Power drop and elevated consumption result. Virtually no risk for motorway drivers.
Symptoms: Power drop at higher load, elevated fuel consumption, occasional particulate filter warning, engine runs rougher
The M256 uses Camtronic variable valve actuation — same technology as M276/M270 with documented failures. Wear on the adjustment unit or solenoid valve is possible. Oil quality is decisive.
Symptoms: Hesitation at low rpm, camshaft position sensor fault code, rough idle, engine warning with power reduction
Direct injection on the M256 inline-six causes carbon deposits on intake valves. Walnut blasting every 60,000–80,000 km recommended.
Symptoms: Hesitation in the lower rev range, rough idle, sporadic misfires on cold start
Rattling on cold start from the wastegate guide bush with design-inherent play. BorgWarner states this is necessary so the wastegate does not stick at operating temperature. Mercedes classes it as state of the art — not a defect.
Symptoms: Rattling or clattering in the first seconds after cold start, disappears after warm-up
Vehicle Weaknesses 10
Incorrectly fitted A/C condensate drain hoses direct water into the interior. Short circuits and fire risk. KBA recall 012644 affects 11,601 vehicles.
On early V167 models, damper rod seals do not meet specification. Leaking hydraulic fluid leads to premature failure.
An incorrectly welded stud on the right-hand side of the vehicle allows water ingress. Electrical connections for the engine, lighting and wipers can fail. Approximately 3,576 vehicles affected.
Incorrectly routed condensate drain hoses direct water into the vehicle interior. Contact with electrics can cause short circuits and fire risk. Recall KBA 012644, 171,463 vehicles worldwide.
On early C167 examples, the damper rod seal cannot meet long-term sealing requirements. Risk of tipping at maximum load and cornering.
Incorrectly routed A/C condensate drain hoses can cause short circuits and fire risk. Approximately 171,463 vehicles worldwide affected.
Incorrectly secured window channel trim strips can detach while driving. Approximately 450,000 vehicles on the 167 platform worldwide affected.
The infotainment system freezes occasionally. Climate control and seat adjustments become non-functional. Software updates only partially improve the situation.
Decorative trim strips on rear doors detach. Around 450,000 vehicles affected. Mercedes covers costs under a goodwill action.
The MBUX system no longer responds to touch inputs or hangs on long journeys. Software updates alleviate the problem but rarely solve it permanently.
Reports & Tests
231 owner complaints filed with NHTSA (2019–2025). Most reported: Engine (61), Electrical (44), Other (36).